Kenmore / Sears Defrost Thermostat, Sensor

Fix frost buildup in your freezer with this defrost thermostat. Controls defrost cycles by sensing evaporator temperature. Simple DIY repair in 30 minutes.

This temperature sensor (thermistor) detects internal appliance temperature and sends readings to the control board so the unit maintains proper cooling. Replacing a failing sensor restores accurate temperature monitoring and helps prevent spoilage. What it does:

• Measures internal temperature and provides a resistance-based signal to the control board
• Helps the control system regulate compressor and defrost cycles
• Commonly causes warm or fluctuating temperatures, prolonged cooling, or temperature-related error codes when failing
• Works as a direct-sensing temperature input — not a user control or switch

• One temperature sensor/thermistor (single part as shown)

• Unplug the appliance or switch off power at the breaker before servicing
• Handle the sensor and its thin leads carefully to avoid damage during removal and installation
• Route and secure wiring so it does not contact moving parts or sharp edges

This defrost thermostat helps control the refrigerator/freezer defrost cycle by sensing evaporator temperature and allowing the heater to run when frost removal is needed. Replaces a failed thermostat to restore normal defrost operation. What it does:

• Closes when the evaporator is cold so the defrost heater can run, then opens when the coil warms to stop defrosting
• Helps prevent excessive frost and ice buildup on the evaporator coil
• Common symptom: visible frost or ice on evaporator, excessive frost buildup, or defrost heater running constantly/ not at all
• Works with the defrost system to maintain efficient cooling performance

• One defrost thermostat

• Disconnect power to the appliance before starting any repair
• Mount on or near the evaporator coil as originally installed; secure wiring away from moving parts
• Inspect the harness and connector for damage; replace if corroded or brittle
• Test for continuity with a multimeter to confirm thermostat function before and after installation

Fixes frost buildup in freezer by controlling defrost cycles. This bi-metal sensor prevents overheating during defrost. Moderately easy repair.

Refrigerator running constantly or freezing food? This defrost thermostat regulates temperature cycles to restore consistent cooling and prevent frost buildup.